PIV. particle image velocimetry using fiji app

So if we have a still image of a jet spray, we can use an app called fiji to be able to find some flow characteristics. For example velocity, average diameter of droplets, etc.

What are Important steps in droplet detection in any PIV software?

· Segmentation – ability to distinguish an object from its background.

Thresholding – we choose the range and separate into black and white. Converts image to binary

Can be Automatic or manual. The computer chooses the objects that fit your definition of pixel size and labels it as a droplet.

· Water shed separation – ultimate eroded points (equidistant points from each edge) are dilated until they touch another black pixel. This is point where a watershed line is drawn. Its done so that droplets out of focus do not get into the counts.